This invention relates to liquid ring pumps and more particularly to liquid ring pumps having lobe liners which rotate on an annular fluid bearing inside a stationary housing.
Liquid ring pumps having rotating lobe liners are well known as shown by such references as Kollsman U.S. Pat. No. 2,609,139 and Russian patent 219,072. In such pumps an annular liner is supported on an annular fluid bearing inside the stationary annular housing of the pump. Rotation of the rotor in the pump causes the pumping liquid in the pump to form into a recirculating annular ring inside the liner. This motion of the pumping liquid causes the liner to rotate in the same direction on its fluid bearing at a speed which is somewhat less than the speed of the pumping liquid. The rotating liner reduces fluid friction losses in the pump because it reduces the amount of rapidly recirculating pumping liquid which is in direct contact with the stationary housing.
The known references showing prior art pumps of the type described above recognize the need to introduce a bearing liquid into the annular clearance between the liner and housing at multiple points around the circumference of the pump. For example, this may be accomplished by withdrawing pumping liquid from the liquid ring at several circumferentially spaced points and conveying that liquid substantially axially from the withdrawal point to an associated bearing liquid introduction channel or aperture. This approach has several disadvantages. For example, it may not be desirable or possible to use ring liquid as the bearing fluid. The ring liquid may not be clean enough for use as the bearing fluid, or it may be desirable to use a bearing fluid which is different from the ring liquid. The liner may have end walls as shown in commonly assigned, co-pending application Ser. No. 635,233, filed Dec. 28, 1990 (hereby incorporated by reference herein) which may prevent withdrawal of liquid from the ring for use as a bearing fluid. Structure like that shown in Russian patent 219,072 necessitates large amounts of external piping for conveying the ring liquid from its multiple outlets to the bearing liquid inlets. Such piping is expensive, may be relatively fragile in some applications, and makes the pump at least appear excessively complex.
In view of the foregoing, it is an object of this invention to improve and simplify liquid ring pumps having rotating liners supported on annular fluid bearings.
It is a more particular object of this invention to improve and simplify the distribution of bearing fluid to the annular fluid bearing on which the rotating liner in liquid ring pumps having such liners is supported.